The study design will be structured on the basis of protocol Yale. Upon emergency wards admission, all patients will be assigned to undergo prompt coronary revascularization. After PCI procedures, hyperglycemic patients will be randomly assigned to intensive glucose control (IGC group) and those treated with conventional glucose control (CGC group). In the patients with In the CGC group, continuous insulin infusion of 50 IU Actrapid HM (Novo Nordisk) in 50 ml NaCl (0.9% using a Perfusor-FM pump) will be started only when blood glucose levels exceeded 200 mg/dl and adjusted to keep blood glucose between 180 and 200 mg/dl. When blood glucose fell <180 mg/dl, insulin infusion will be tapered and eventually stopped. In the IGC group, insulin infusion will be started when blood glucose levels exceeded 140 mg/dl and adjusted to maintain glycemia at 80-140 mg/dl. During insulin infusion, oral feeding will be stopped and parenteral nutrition (13±5 Kcal/kg-1/day-1) will be started. After the start of insulin infusion protocol a glycemic control will be provided every hour in order to obtain three consecutive values that were within the goal range. The infusion will be lasted until stable glycemic goal (ICG group: 80-140 mg/dl; CGC group: 180-200 mg/dl) at least for 24 h. After glycemic goal will be maintained for 24 h, a parenteral nutrition was stopped and feeding will be started according to European guidelines. Subcutaneous insulin will be initiated at the cessation of the infusion. After discharge from the hospital, insulin will be given as short-acting insulin before meals and long-acting insulin in the evening for 30 days from PCI in both group. In IGC group, the treatment goal will be a fasting blood glucose level of 90-140 mg/dl and a non-fasting level of <180 mg/dl. In CGC group, the treatment goal will be fasting blood glucose and postprandial levels of <200 mg/dl. With regard to the full medical therapy, the protocol stated that the use of concomitant treatment should be as uniform as possible and according to evidence-based international guidelines for ACS. After 30 days from PCI, all patients with established diabetes and newly diagnosed diabetes will be managed and followed for 6 month after PCI, as outpatients, to maintain HbA1c <7% and blood glucose level of 90-140 mg/dl and a non-fasting level of <180 mg/dl.